APPLICATION OF THE LATTICE BOLTZMANN METHOD TO LIQUID-SOLID PHASE CHANGE IN FREE SURFACE FLOW:AN EXAMPLE OF MONGOLIAN SMALL HYDROPOWER PLANT

摘要

The presence of ice hinders the operation of small hydropower plants in cold regions like Mongolia. In order to study this problem, we propose a numerical model for analyzing the liquid-solid phase changes that occur in a free surface flow. This model is formulated using the lattice Boltzmann method (LBM). The single phase free surface model, along with the immersed boundary condition, is used to model the free surface flow and solid phase. The thermal lattice Boltzmann (LB) equation is combined with a non-iterative enthalpy based formulation to simulate heat transport and phase changes. These models are integrated in a way that holds physical relation. The performance and accuracy of the model is validated using experimental evaluations. The formation of open water in the downstream channel of the hydropower plant is successfully simulated to demonstrate the performance of the model. Results indicate that the proposed model can be used for stud-ying measures to control downstream ice in hydropower plants. It can also be applied to study the ice phenomena in open channel flows.